1. Field of the Invention
The present invention relates to a receiving technology, and it particularly relates to a receiving apparatus that receives packet signal.
2. Description of the Related Art
Road-to-vehicle communication has been under investigation in an effort to prevent collision accidents of vehicles on a sudden encounter at an intersection. In a road-to-vehicle communication, information on conditions at an intersection is communicated between a roadside unit and an in-vehicle unit. Such a road-to-vehicle communication requires installation of roadside units, which means a great cost of time and money. In contrast to this, an inter-vehicular communication, in which information is communicated between in-vehicle units, has no need for installation of roadside units. In that case, current position information is detected in real time by GPS (Global Positioning System) or the like and the position information is exchanged between the in-vehicle units. Thus it is determined on which of the roads leading to the intersection the driver's vehicle and the other vehicles are located.
When packet signals are received in wireless LAN compatible with the IEEE 802.11 standard and the like, the gain or amplification factor of an amplifier for amplifying the packet signals is set based on STF (Short Training Field) placed in the beginning of packet signal. The amplification suited to the received packet signal is not done if the accuracy in the setting of gain is low.